This invention relates to a spring locking device for a connector, which prevents connected male and female connector members of the connector from being disconnected as by external forces, and more particularly to a spring locking device for a connector, which prevents any disconnection of connected connector members of the connector and at the same time serves to reduce the number of parts of the connector.
For example, spring locking mechanisms as shown in FIGS. 1a and 1b have been widely used in order to prevent fitted connected male and female connector members from being disconnected by external tensile forces acting upon a connection cable and the like.
A locking member 1 of the spring locking mechanism as shown in FIG. 1 is made of a springy metal wire which is bent to have two support pins 1a, two legs 1b perpendicular to the support pins, and a rhombic latch portion 1c having a width wider than a distance between the two legs 1b. On the other hand, a mounting flange 2a of a metal shell 2 of a female member A is formed with bearings 2b which are formed by slitting and then raising parts of the flange 2a away therefrom by punching as shown in FIG. 1b. The locking members 1a are mounted to the female connector member A by inserting the support pines 1a into the bearings 2b.
Moreover, a mounting flange 3a of a metal shell 3 of a male connector member B is formed with leg guide slits 3b having a width narrower than the distance between the legs 1b and locking apertures 3c at inner ends of the leg guide slits 3b and continuous thereto. Diameters of the locking apertures 3c are larger than the width of the leg guide slits 3 but smaller than the width of the rhombic latch portion 1c.
When the female and male connector members have been fitted and connected, the locking member 1 are turned with the rhombic latch portions 1c against their spring forces so that the legs 1b are forced through the leg guide slits 3b and positioned in the locking apertures 3c. The legs 1b of the locking member 1 are once narrowed by the leg guide slits 3b and again permitted to expand in the locking apertures 3c by their spring forces, so that the locking members 1 are prevented from being removed through the leg guide slits 3b and further resist to any external pulling forces with the aid of the rhombic latch portions 1c wider than the locking apertures 3c. The connected female and male connector members are thus prevented from being disconnected by external forces.
With the spring locking mechanism of the prior art as above described, after the rhombic latch portions 1c of the locking members 1 have been pressed inwardly to narrow the distances between the legs 1b, the support pins 1a of the locking members 1 are positioned between the bearings 2b of the female connector member A and the rhombic latch portions 1c are then released. As a result, the legs 1b expand by their springy return forces to insert the support pins 1a into the bearings 2b.
In the arrangement of the locking mechanism of the prior art, the locking members 1 are likely to be removed from the connector because the support pins 2a are apt to be dislodged from the bearings owing to narrowed distances between the legs 1b and other reasons for example when the legs 1b are inserted in the leg guide slits 3b for locking.
In order to overcome this problem, in the prior art for example as shown in FIGS. 3a-3c a removal preventing projection 4 is provided between the two bearings 2b and legs 1b of locking members 1 are bent as shown at 1b in FIG. 4b which is a side view of the locking member 1 of FIG. 4a. Therefore, when the legs 1b are inserted in the leg guide slit 3b, the removal preventing projection 4 is positioned between the bottoms of the legs 1b to prevent any removal of the support pins 1a from the bearings 2b.
In such a solution, however, a metal plate 5 is separately needed which has bearings 2b and removal preventing projections 4 by punching and bending. The metal plate 5 is then fixed to the mounting flange 2a of the connector member by means of eyelets or the like as shown in FIG. 3a. As an alternative, an insulating block 6 of a connector member is formed integrally with removal preventing projections 4 so that when a mounting flange 2a is secured on the insulating block 6, the removal preventing projections 4 extend beyond the mounting flange 2a through apertures previously formed in the mounting flange 2a as shown in FIG. 3b or 3c.
Therefore, the number of parts constituting the connector is increased and dies for molding the insulating block 6 are complicated to increase manufacturing cost of the connector.